Validation of an E-cigarette Purchase Task in Advanced Generation Device Users

Moral injury among women military veterans and demand for cigarettes: A behavioral economic investigation using a hypothetical purchase task

OBJECTIVES

Unlike the United States general population, veteran women - as opposed to veteran men - have greater smoking prevalence; yet, little is known regarding factors that influence smoking in veteran women. The purpose of this study was to begin examining the relationship between a psychological concept known as moral injury and demand for cigarettes among veteran women.

METHODS

Veteran women who smoke (n = 44) were recruited for this cross-sectional study from Amazon MTurk, Reddit, and a veteran-serving non-profit organization in June-July 2023. Consenting participants received $2 for completing the cigarette purchase task (CPT), Fagerstrom Test for Nicotine Dependence (FTND), and the military version of the Moral Injury Symptom Scale (MISS-M-SF). We examined five CPT demand indices and calculated a modified exponential demand model stratified by moral injury severity status (i.e., probable vs. unlikely).

RESULTS

Probable morally injured women exhibited significantly higher relative reinforcing value (RRV) for smoking than unlikely morally injured women (F1, 920 = 9.16, p = 0.003). Average cigarette consumption at $0 (i.e., Q0) was 48.56% higher (M = 22.24 vs. M = 13.55) in probable compared to unlikely morally injured women (p = 0.04, Hedge's g = 0.74). FTND scores were significantly correlated with Pmax (i.e., demand elasticity point) and Omax (i.e., maximum expenditure) values in both populations (rs = 0.42-0.68, ps < 0.05).

CONCLUSIONS

We provide preliminary evidence of the relatively high RRV of smoking in morally injured veteran women. Continued research is needed to refine the characterization of this relationship.

The electronic nicotine delivery system (ENDS) purchase task: Are results sensitive to price framing?

Extension of the cigarette purchase task (CPT) to electronic nicotine delivery systems (ENDS) is complicated by the heterogeneous nature of this product class, as ambiguity exists regarding the appropriate price-frame (i.e., unit of the product being purchased). We explored correlations between ENDS purchase task (E-CPTs) outcomes featuring two common price-frames: 10 puffs and 1 mL of liquid. Adult exclusive ENDS users (N = 19) and dual users of ENDS and cigarettes (N = 16) completed two own-brand E-CPTs. One E-CPT used "10 puffs" as its price-frame; the other used "1 mL of liquid." Five outcomes were generated for each E-CPT: breakpoint, intensity, Omax, Pmax, and α. Exploratory Factor Analyses (EFA) considered how these outcomes captured latent structures of demand for ENDS. Spearman correlations in E-CPT outcomes assessed within-person variation between price-frames. Analyses also considered whether correlations differed by user group. E-CPT outcomes were highly correlated across price-frames (ρs > 0.57, ps < .001), and EFA revealed little difference in how outcomes from the tasks loaded onto two latent structures of demand ("Persistence" and "Amplitude") reported in the previous literature. The magnitude of correlations for E-CPT outcomes tended to be higher for exclusive ENDS users than for dual users. Participant responses to purchase task outcomes were similar across two E-CPT price-frames. Using "10 puffs" as a price-frame may be a generalizable approach among heterogenous groups of ENDS users, but researchers should consider their target population and structure the E-CPT to reflect participants' knowledge and purchasing behaviors. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Effects of short-term nicotine deprivation on delay discounting among young, experienced, exclusive ENDS users: An initial study

Delay discounting describes how rapidly delayed rewards lose value as a function of delay and serves as one measure of impulsive decision-making. Nicotine deprivation among combustible cigarette smokers can increase delay discounting. We aimed to explore changes in discounting following nicotine deprivation among electronic nicotine delivery systems (ENDS) users. Thirty young adults (aged 18-24 years) that exclusively used ENDS participated in two laboratory sessions: one with vaping as usual and another after 16 hr of nicotine deprivation (biochemically assessed). At each session, participants completed a craving measure and three hypothetical delay discounting tasks presenting choices between small, immediate rewards and large, delayed ones (money-money; e-liquid-e-liquid; e-liquid-money). Craving for ENDS significantly increased during short-term nicotine deprivation relative to normal vaping. Delay discounting rates in the e-liquid now versus money later task increased (indicating a shift in preference for smaller, immediate rewards) following short-term nicotine deprivation relative to vaping as usual, but no changes were observed in the other two discounting tasks. Short-term nicotine deprivation increased the preference for smaller amounts of e-liquid delivered immediately over larger, monetary awards available after a delay in this first study of its kind. As similar preference shifts for drug now versus money later have been shown to be indicative of increased desire to use drug as well as relapse risk, the findings support the utility of the current model as a platform to explore interventions that can mitigate these preference shifts. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The interactive effects of JUUL flavor and nicotine concentration on addiction potential

Prior research suggests that flavors can influence the pharmacological effects of nicotine. We used commercially available JUUL pods to examine whether preferred menthol versus tobacco flavor increased the addictive potential of nicotine per se. This study recruited 15 regular JUUL e-cigarette users to complete a 2 × 2 factorial crossover trial using an entirely remote video format. Participants completed a sampling baseline session to identify preferred JUUL flavor (menthol vs. tobacco) followed by four counterbalanced experimental sessions separated by ≥ 48 hr: (a) low-nicotine dose (3% JUUL)/nonpreferred flavor; (b) low dose/preferred flavor; (c) high-nicotine dose (5% JUUL)/nonpreferred flavor; and (d) high dose/preferred flavor. In each experimental session, participants completed a puffing procedure followed by subjective ratings of e-cigarette liking and wanting (ELW), urges, and reinforcement using a JUUL pod purchase task. There was a dose-by-flavor interaction for average ELW (F = 4.58, p = .041) in which ELW was significantly greater for the preferred than the nonpreferred flavor at the low-nicotine dose but not the high-nicotine dose. There were also dose-by-flavor interactions for pre- to post-puffing change in overall urge to vape (F = 5.97, p = .021) and urge strength (F = 4.96, p = .049), with greater reductions in overall urge/strength for the preferred compared to the nonpreferred flavor at the low but not the high dose. We found no significant interaction effects for purchase task outcomes. Using a fully remote experimental puffing procedure, our findings suggest preferred flavors increase the rewarding effects most for lower nicotine e-cigarettes. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Behavioral economic relationship between cannabis and cigarettes: Evidence from hypothetical purchase tasks

BACKGROUND

In the United States (U.S), cannabis policies have been increasingly liberalized whereas tobacco policies have been increasingly stringent. Given the high prevalence of cannabis and tobacco dual use, there are concerns that a policy regulating one substance may unintendedly influence the other. This study examined the responsiveness of the demand for cannabis joints and cigarettes when price varied.

METHODS

The study included 338 adult participants (21+) who used both cannabis and tobacco and lived in one of the U.S. states with recreational cannabis legalized by the time of interview in 2019. They completed hypothetical purchase tasks to indicate the quantity desired of cannabis joints and cigarette packs 1) when only one substance was available with escalating prices and 2) when both substances were concurrently available with escalating prices of cannabis joints and a fixed price of cigarette packs. We estimated 1) the own-price elasticity of demand for each substance using nonlinear exponential demand model, and 2) the cross-price elasticity of demand at aggregate level using nonlinear exponential demand model and at individual level using log-linear demand model.

RESULTS

The estimates for the rate of change of own-price elasticity (α) were 0.0011 (SE = 0.000039, p < 0.001) for cannabis joints and 0.00095 (SE = 0.000037, p < 0.001) for cigarette packs. The aggregate-level estimates of cross-price elasticity (I = 13.032, SE = 0.34, p < 0.001; β = 0.0029, SE = 0.0021, p > 0.05) suggest an independent relationship between the two substances. At individual level, 78.70% of the participants treated the two substances as independent, 17.46% as complements, and 3.85% as substitutes.

CONCLUSIONS

For most adults who used both cannabis and tobacco in the U.S., cannabis joints and cigarettes had an independent relationship. Policies regulating the price of cannabis may not have large unintended consequences on cigarette use.

Validity of a little cigars/cigarillos purchase task in dual users of cigars and cigarettes

INTRODUCTION

Hypothetical purchase tasks have been widely used to assess the reinforcing value of tobacco products. However, a task has not yet been validated for little cigars and cigarillos (LCCs), a popular tobacco product class among vulnerable populations. This study sought to validate the LCC Purchase Task (LCCPT) in a sample of experienced LCC smokers.

METHODS

Data were collected from 65 young adult (18-34 years) LCC and cigarette dual users (78.5% male) in Connecticut (2018-2020). Participants completed the usual-brand LCCPT for consumption in 24 h at increasing prices. We calculated four observed demand indices: intensity (consumption at $0), breakpoint (price after which consumption reaches 0), O_max (maximum daily expenditure), and P_max (price at which daily expenditure was maximized). Two indices were estimated from demand curves: Q₀ (predicted consumption as price approaches $0) and price-sensitivity (sensitivity to price increases). Spearman correlations and multivariable regressions examined the associations between demand indices, self-reported cigar use, and dependence.

RESULTS

Correlations were in expected directions. All indices except breakpoint and P_max were positively correlated with use, and all indices were correlated with multiple measures of dependence. Overall, greater demand and expenditure for LCCs and lower sensitivity to price changes were correlated with greater use and dependence. In regression analyses intensity and price-sensitivity showed the strongest relationships with use and dependence.

CONCLUSIONS

The validity of the LCCPT was supported in a sample of experienced LCC smokers. This instrument can be incorporated into other protocols to assess the abuse liability of LCCs.

Vapers exhibit similar subjective nicotine dependence but lower nicotine reinforcing value compared to smokers

INTRODUCTION

E-cigarette use has increased rapidly over the last 10 years, mostly among smokers and ex-smokers. Although there may be some degree of dependency on nicotine via e-cigarette use, the nature of this dependency is poorly understood. The aim of this paper is to use tasks from behavioural economics to compare the value that smokers place on tobacco cigarettes to the value that vapers place on e-cigarettes.

METHOD

Exclusive current smokers (n = 25) and vapers (n = 20) attended one session where they completed the Cigarette/e-cigarette Dependence Scale, the Cigarette/e-cigarette Purchasing Task (CPT) and the Concurrent Choice Task (CCT). The CPT requires participants to indicate how many puffs of their chosen product they would purchase at increasing price points. The CCT requires participants to choose between earning a money point or a point towards a cigarette/e-cigarette after being presented with a neutral, money or cigarette/e-cigarette cue.

RESULTS

Overall scores on the self-report scales suggest a comparable level of dependency between smokers and vapers. The CPT revealed that vapers are more sensitive than smokers to escalating costs as consumption declined as costs increased. On the CCT, when primed with money, vapers showed a decrease in choosing e-cigarettes.

CONCLUSION

These findings suggest that, on behavioural economic tasks, tobacco cigarettes have a higher relative value than e-cigarettes. Vapers appear to place a lower limit on what they will spend to access e-cigarettes and more readily choose money over e-cigarette puffs when primed by money cues.

E-Cigarette Demand: Impact of Commodity Definitions and Test-Retest Reliability

INTRODUCTION

Behavioral economic demand provides a multidimensional understanding of reinforcement. Commodity purchase tasks are an efficient method for measuring demand in human participants. One challenge in translating these procedures to electronic nicotine delivery systems (ENDS or e-cigarettes) is defining commodity units given the lack of standardization in the e-cigarette marketplace.

AIMS AND METHODS

The purpose of this study was to directly compare methods of operationalizinge-cigarette purchases, puffs, cartridges, and mLs liquid, using a within-subject design. Participants (N = 132) reporting past week e-cigarette use were recruited using crowdsourcing. Purchase tasks were completed operationalizing e-cigarette units as puffs or cartridges at baseline and puffs or mLs liquid at a 3-month follow-up.

RESULTS

Bivariate associations supported convergent and discriminant validity with the largest effect size correlations for intensity and elasticity observed for the puff version. Interaction models suggested that product preferences moderated the relationship between time-to-first use and cartridge demand with larger effect size correlations among persons reporting a preference for JUULs, but weaker relationships among persons reporting other device preferences. Puff intensity (rxx = .61) and elasticity (rxx = .62) showed good test-retest reliability for participants reporting stable consumption, but poor test-retest reliability for individuals with changed consumption levels (intensity rxx = -.08; elasticity rxx = -.10).

CONCLUSIONS

This study highlights the relevance of commodity definitions in the e-cigarette purchase task. Puffs as an experimental commodity may provide flexibility for studying e-cigarette demand in heterogenous or unknown populations, whereas more tailored or personalized approaches like cartridge or mL-based tasks will likely be helpful when studying known subgroups.

IMPLICATIONS

The commodity purchase task procedure is widely used for understanding cigarette and e-cigarette demand in nicotine dependence research. This study evaluates the importance of operational definitions of e-cigarette commodities in the purchase task (ie, puffs, cartridges, or mLs liquid). Puffs may provide a more flexible commodity unit when evaluating e-cigarette demand in general or heterogenous populations, whereas device-specific units may prove more valuable when studying populations with consistent and known product use.

Exclusive E-Cigarette Users Report Lower Levels of Respiratory Symptoms Relative to Dual E-Cigarette and Cigarette Users

INTRODUCTION

Exclusive e-cigarette use has been shown to be associated with reduced levels of respiratory symptoms relative to smoking combustible cigarettes; this association has been less frequently studied in smokers using advanced-generation e-cigarette devices. Advanced-generation devices generate denser vapor than either early generation or pod-style devices, and engender longer inhalations; these vaping topography patterns may contribute to respiratory symptoms.

METHODS

In a single-session, cross-sectional study of exclusive e-cigarette users (N = 59) and dual users of e-cigarettes and cigarettes (N = 54), participants completed questionnaires, including the American Thoracic Society Questionnaire (ATSQ) and were videotaped vaping their own device in the lab for 1 hour. Using a hierarchical regression method, we examined whether topography variables, level of nicotine concentration used in their e-cigarette device in the past month, e-cigarette dependence, amount of e-cigarette use in the past month, and smoking status (any smoking in the last month vs. none) predicted ATSQ score severity.

RESULTS

There was a significant mean difference in ATSQ score across smoking status, with greater ATSQ scores for vapers who also smoked cigarettes (19.0, SD = 6.7) than for exclusive vapers (13.4, SD = 5.3). In the final model, of the predictors of interest, only cigarette smoking status predicted significantly greater ATSQ scores (overall F = 2.51, p = .006; R2 = .26; smoking status β = 0.39, p < .0001).

CONCLUSIONS

Findings suggest that differences in respiratory symptoms between dual and exclusive e-cigarette users appear to be attributable to combustible cigarette smoking, rather than more intense or frequent e-cigarette use across groups.

IMPLICATIONS

In this comparison of exclusive advanced-generation vape device users (N = 59) versus dual users of these devices and combustible cigarettes (N = 54), we set out to determine the extent to which smoking status and e-cigarette use variables predicted self-reported respiratory symptom severity. We found that dual users showed greater respiratory symptom severity (ATSQ scores) than exclusive vapers. Despite examining vaping topography and other variables, smoking status and race were the only significant predictor of respiratory symptoms. We conclude that combustible cigarette use, not individual vaping topography, likely accounts for differences in respiratory symptoms between dual users and exclusive vapers.